Incandescent lamp.



v M. M. MERRITTL INGANDESGBNT LAMP. APPLICATION FILED 113.24] 19 06.

. PaLented"N0v.2.8,1911.

I WITNEZEEE lSL I lNvizw-rm x;

' ATTY'S COLUMBIA PLANOGIIAPH CO.. WASHINGTON D c UNITE STATES Arum onnrca.

MATTHEW M. MERRITT, 0F MIDDLETON, MASSACHUSETTS, ASSIG-NOR TO NATIONAL ELECTRIC LAMP COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF NEW JERSEY.

INCANDESCENT LAMP.

Specification of Letters Patent. Patented NOV. 28, 1911.

Application filed February 24, 1906-. Serial No. 302,672.

To all whom it may concern:

Be it known that I, MATTHEW M. MERRITT,

other words, the substitution, or attempted substitution, of a new filament for the old one when the latter is burned out or otherwise rendered useless or inefficient. It is a common practice to purchase at a relatively slight cost high grade lamps thus burned out, open the end or tip of the lamp and replace the old filament with a fresh one. The new filament having been attached to the leading-in wires, the lamp is exhausted by the usual process, the bulb scaled up, and the renewed or converted lamp in condition again for use. This renewing process is he quently conducted by irresponsible persons;

lacking the necessary skill and knowledge in the art and employing inferior materials, so that its product, in any event an inferior one, is Very often a low grade lamp, though having every appearance of a high grade one.

My invention aims to correct this practice,

preventing possible injury to the reputation of the maker of the'original lamp and deception of the public as well. In the disclosed embodiment of my invention this is accomplished by originally so constructing the lamp that when it is subjected to one or more of the usual steps of the renewing.

process, such injury is occasioned to the lamp itself or such obstructions interposed to the practical consummation of the renewing process that renewal becomes commercially infeasible.

My invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one or more specific embodiments thereof, while its scope will be more particularly pointed out in the appended claims. 7

Referring to the drawings,Figure 1 shows a lamp embodying one form of my invention, and Figs. 2, 8, 4 and 5 show modifications thereof. 1

Referring to the drawings and to the embodiment of my invention which I have selected for illustration in Fig. 1, there is shown a common form of incandescent lamp provided with the usual glass bulb a, cemented or otherwise secured in the usual fashion to and within the metal socket Z2 and having the usual form of glass stem 0, through which pass the leading-in wires (Z, terminating in the usual sealed-in platinum ends 6, the latter connected to the filament 7.

One of the characteristics of an old or burned-out lamp, and invariably where it has been used any length of time, is a darkening or clouding of the bulb, which is caused by a deposit of finely divided matter thrown off by the filament or joints during incandescence. This deposit is a considerable factor alone in reducing the effective candle power of a lamp and its removal constitutes one of the usual and first steps in the renewing process after the opening of the bulb tip. This is ordinarily accomplished by subjecting the lamp, while the latter is slowly revolved, tov some intense heat, such as the heat of an alcohol or hydrogen vapor torch. The heat which is usually imparted to the lamp and necessary to volatilize and drive ofi the solid deposit is probably not less than 500 or 600 F ah., and, of course, abnormally in excess of any heat to which the lamp bulb is ever subjected during its customary and intended use and greatly in excess of the maximum heat which can be interiorly imparted to the bulb by the incandescent filament. For example, the heating of the bulb of an ordinary sixteen candle power lamp can scarcely exceed 150 Fah. even when the filament is carrying the maximum current of which it is capable. In the described embodiment of my invention I. take advantage of. the-abnormally high degree of. heat which is required to carry out this or other steps of the renewing process and provide the lamp with means responsive to .such

heat for working injury to the lamp, and preferably to the lamp bulb. This may be accomplished in various ways, but in Fig. 1 I have shown the lamp bulb provided, as at g, with portions of abruptly contrasted out the bulb as above described as to produce a puncture or fracture of the bulb sufiicient to prevent a subsequent produc tion and maintenance therein of a commercial vacuum. WVhile the fracture may be sufficient to cause collapse of the bulb, it is unnecessary actually that the lamp shall be visibly broken or fractured, since the production of a minute crack or puncture invariably prevents the maintenance of the,

required vacuum. The particular location of the groove or incision is immaterial, although preferably it should-be where it will be exposed to the most sudden and intense heat. My invention also is not limited to any particular number of incisions or to their relative position and in Fig. 2 I have shown a similar lamp and having a plurality of adjacent incisions g, which may be mere surface cuts, located near the rounded end of the bulb where the intense heat employed in burning out would probably have the greatest fracturing efiect. As a matter of fact, a plurality of incisions adjacent each other, whether intersecting or not, expedite the fracture which tends to run from one to another.

The particular shape of the incision or other formation by which the abruptly differentiated thickness of bulb walls is obtained is immaterial so long as it produces the'puncturing or fracturing effect desired. In Fig. 8 I have shown a lamp having a plurality of grooved cuts 9, 9 formed in the end of the bulb and converging toward the tip. This is a particularly effective location, for another step of the renewal process, ordinarily subsequent to the burning out of the deposit described, involves the welding on to the perforated tip of a short glass stem or tubulature, through which the subsequent exhaustion of the lamp is effected. This requires the heating of the tip of the lamp in the blow pipe flame, result ing in highly heating the adjacent walls of the bulb. With the grooves located as in Fig. 3 the lamp tends to fracture during the burning out process. If this fails, puncture is almost certain to occur when-it is attempted to weld on the tubulature.

It will be obvious that other means than incisions may be employed for causing unequal expansion of adjacent portions of the bulb walls. For example, irregular formations of any suitable nature may be employed and in Fig. 4 I have shown the lamp bulb provided with a groove 9 produced by forming a swelled or thickened portion h adjacent a contracted or thinner portion, such formation being produced adjacent the attachment of the metal socket, which latter will more or less assist the thickened portion in conducting away the heat and render more certain the unequal expansion between 'the two sect-ions of differentiated thickness.

In Fig. 5 I have shown considerable areaz' of the bulb, purposely and materially weakened as compared with other parts, and particularly the adjacent portion thereof. This may be accomplished in any suitable or desired fashion, as for example, in a subsequent step or process after the initial formation of the bulb. It will be understood that in Fig. 4: as well as in Fig. 5 no attempt is made to show accurately the true thickness of the bulb walls.-

It is to be understood that my invention has application to other means for prevent-- ing renewal than those described and where manifestations resulting from the applica-- tion of abnormal heat are relied upon to means for fracturing other parts than the bulb proper, of the lamp-space inclosing walls, such for example as the stem. It is also to be understood that, while I have herein described and illustrated in detail several embodiments of my invention illustrating specifically the principles thereof, the invention is not to be limited to the details herein shown or described, but that exten- L sive modifications therein may be made without departing from the spirit thereof.

Claims:

1. A non-renewable incandescent lamp having a filament, a bulb, and means responsive to an abnormally high degree of heat for causing fracture of the lamp bulb.

2. A non-renewable incandescent lamp having a filament, abulb, and means for causing puncture of the lamp bulb on attempted renewal of the lamp.

3. A non-renewable incandescent lamp having a filament, a bulb, and means for causing the puncture of the lamp bulb, said means being responsive to the great heat applied in burning out the deposit in the bulb of. the old lamp.

4. A non-renewable incandescent lamp having a purposely applied incision upon the bulb of insuflicient depth to afiect the useful strength thereof but sufficient to cause puncture of the bulb when the latter is subjected to an abnormal heat.

5. A non-renewable incandescent lamp having a purposely weakened area insuflicient to affect the useful strength thereof but sufficient to cause puncture of the bulb when the latter is subjected to an abnormal heat.

6. A non-renewable lamp having a filament, a bulb, and means for causing the unequal and disrupting expansion of difierent parts of the lamp bulb when the latter is abnormally heated.

7. An incandescent lamp having a filament,-a bulb, and means associated with its bulb for localizing a puncture therein when the bulb is abnormally heated.

8. A non-renewable incandescent lamp having a bulb provided with portions of abruptly difierentiated thickness.

9. An incandescent lamp having a bulb a provided with the incision g.

10. An incandescent lamp having a bulb and a groove in the outer face thereof of suitable location and depth to cause fracture of the bulb thereat when the lamp is heated to an abnormal degree.

11. A non-renewable incandescent lamp having a filament and a bulb of purposely irregular formation to localize a puncture therein on the application of an abnormally high degree of heat to the lamp.

12. A non-renewable incandescent lamp having a plurality of adjacent surface incisions for causing a puncture thereat on the abnormal heating of the lamp.

13. A non-renewable incandescent lamp having a filament, a bulb, and means applied after the completion of the lamp for causing injury to the walls of the lamp space on the attempted renewal of the lamp.

14:. A non-renewable incandescent lamp having a filament, a lamp bulb, and means associated with the lamp bulb for fracturing the same.

having a filament, a bulb, and means responsive to the application of a high degree of external heat for causing injury to the inclosing walls of the lamp space while unaffected by internal heat generated by the passage of the maximum current of which its filament is capable of standing.

17. A non-renewable incandescent lamp having a filament, a bulb, and means associated with the lamp for causing injury to the walls of the lamp space on the attempted renewal of the lamp.

18. A non-renewable incandescent lamp having a filament, a stem, a bulb, and exterior fracturing means for causing injury to the lamp on the attempted renewal thereof.

19. A non-renewable incandescent lamp having a filament, a stem, a bulb and means applied externally t0 the lamp for causing injury on the attempted renewal thereof.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

MATTHEW M. MERRITT.

Witnesses:

NINA B. SHIRLEY, THoMAs B. Boo'rH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.. 

